A steer-by-wire system is a steering system that eliminates mechanical linkages between the steering wheel and the driving wheels of a vehicle. This steering system receives a steering wheel rotation signal via an electronic control unit (ECU) and operates a steering motor connected to the driving wheels in accordance with the steering wheel rotation signal, thereby steering the vehicle.
Since steer-by-wire systems eliminate mechanical linkages which are usually provided in conventional steering systems, the steer-by-wire systems provide many advantages such as increasing layout flexibility in configuration of a steering system, improving fuel efficiency, eliminating disturbances transmitted from wheels, etc.
Steer-by-wire systems also have a disadvantage that the proper steering feedback information cannot be provided to a driver, due to mechanical disconnections between a steering wheel and driving wheels.
For example, conventional steering systems need not generate steering wheel reaction torque because they have mechanical linkages such as a universal joint or the like, but steer-by-wire systems need to generate steering wheel reaction torque or restoring reaction torque using a motor or the like because they do not have mechanical linkages.
In addition, conventionally, when tires (i.e. wheels) cannot rotate any further beyond a rotation angle limit, a steering wheel can further rotate. Therefore, it is necessary to restrict the rotation of the steering wheel of a vehicle.
Therefore, regarding the steer-by-wire system, a technology for limiting the maximum rotation angle of a steering wheel is required, and various mechanisms that can mechanically limit the maximum rotation angle of a steering wheel have been recently suggested.
However, existing steer-by-wire systems still have a problem that space utilization efficiency is low because a rotation restriction mechanism and a steering wheel reaction torque generation mechanism are separately provided.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.